Optical layered body, polarizing plate, display panel, and image display device

Abstract

The present invention provides an optical layered body having excellent scratch resistance while having antireflective performance. The present invention relates to an optical layered body including a light-transmitting substrate; and at least an antiglare layer and a low refractive index layer disposed in the stated order on one surface of the light-transmitting substrate, wherein a luminous reflectance (%) is 3.0% or less, and the low refractive index layer has an arithmetic average roughness Ra of projections and depressions of 4 nm or less and a ten-point average roughness Rz of the projections and depressions of 60 nm or less, where the Ra and the Rz are measured in any 5-μm square region of a surface of the low refractive index layer.

1 . An optical layered body comprising:
 a light-transmitting substrate; and   an antiglare layer and a low refractive index layer disposed in the stated order on one surface of the light-transmitting substrate,   wherein a luminous reflectance (%) is 3.0% or less, and   the low refractive index layer has an arithmetic average roughness Ra of projections and depressions of 4 nm or less and a ten-point average roughness Rz of the projections and depressions of 60 nm or less, where the Ra and the Rz are measured in any 5-μm square region of a surface of the low refractive index layer.   
     
     
         2 . The optical layered body according to  claim 1 ,
 wherein the surface of the low refractive index layer has a hardness of 440 MPa or more as measured by a nanoindentation method at a penetration depth of 30 nm.   
     
     
         3 . An optical layered body comprising:
 a light-transmitting substrate; and   an antiglare layer and a low refractive index layer disposed in the stated order on one surface of the light-transmitting substrate,   wherein a luminous reflectance (%) is 3.0% or less, and   the low refractive index layer has an arithmetic average roughness Ra of projections and depressions of 1.5 nm or less and a ten-point average roughness Rz of the projections and depressions of 30 nm or less, where the Ra and the Rz are measured in any 5-μm square region of a surface of the low refractive index layer, and   a hardness measured by a nanoindentation method at an indenter penetration of 300 nm is higher than a hardness measured by the nanoindentation method at an indenter penetration of 30 nm.   
     
     
         4 . The optical layered body according to  claim 1 ,
 wherein the surface of the low refractive index layer has a water contact angle of 1020 or less.   
     
     
         5 . The optical layered body according to  claim 1 ,
 wherein the low refractive index layer contains hollow silica fine particles.   
     
     
         6 . A polarizing plate comprising:
 a polarizing element; and   the optical layered body according to  claim 1 , on a surface of the polarizing element.   
     
     
         7 . A display panel comprising
 the optical layered body according to  claim 1 , or a polarizing plate comprising:   a polarizing element; and   the optical layered body according to  claim 1  on a surface of the polarizing element.   
     
     
         8 . An image display device comprising
 the optical layered body according to  claim 1 , or a polarizing plate comprising:   a polarizing element; and   the optical layered body according to  claim 1  on a surface of the polarizing element.